Simulating form and function of root systems: efficiency of nitrate uptake is dependent on root system architecture and the spatial and temporal variability of nitrate supply

Abstract

Summary1. Root-system architecture, and plastic variation in architecture and physiological function, influence the capacity of plants to acquire nutrients from non-uniform soil. Previous theoretical analyses of the relationship between root architecture and nutrient acquisition have largely assumed uniform soils and unresponsive root systems. We extend these studies by considering non-uniform nutrient supply and plasticity in root growth and uptake physiology. 2. Using modelling, we investigated the growth and nitrate uptake of two extreme theoretical architectural types: dichotomous (highly branched) and herringbone (sparsely branched). Root systems with plastic or non-plastic root-growth and nitrateuptake responses, supplied with non-uniform distributions of soil nitrate, were simulated. 3. The simulated herringbone root system had a higher nitrate-uptake efficiency (NUE, nitrate-N m − 3 soil) when supply varied spatially and temporally (compared with variation in space alone), and NUE was affected only by the capacity to elevate uptake kinetics locally. In contrast, the efficiency of the dichotomous root system decreased under spatially and temporally dynamic nitrate supply (compared with static supply), and was influenced only by the capacity to proliferate roots in nitrate patches. 4. These results suggest that root-system NUE is not solely a function of the iontransport characteristics of soil, but is also influenced by the transitory nature of the nutrient source and the structure of the root system.

A dynamic root system growth model based on L-Systems

“…Dunbabin et al (2006Dunbabin et al ( , 2002 predicted water and nutrient uptake, in the presence of exudates (Dunbabin et al 2006), by integrating RootMap into a simulation environment. Dunbabin et al (2004) analysed the effect of different root system architectures on nitrate uptake efficiency. Walk et al (2006) used SimRoot to assess the trade off effects of different root system morphologies on phosphorus acquisition.…”

Reduced Root Cortical Cell File Number Improves Drought Tolerance in Maize

“…Rooting depth is important for the acquisition of mobile nutrients, including nitrate and sulfate, particularly in soils with high leaching potential. Evidence for this comes from modeling studies, where it has been shown that deeper roots could significantly improve the acquisition of nitrogen (Dunbabin et al, 2004;Postma and Lynch, 2011b;Dathe et al, 2013). Reduced CCFN also may affect root hydraulic conductivity, because a smaller radial path Figure 9.…”

Natural Variation as a Tool to Investigate Nutrient Use Efficiency in Plants

“…The uptake efficiency is dependent on the root system architecture (Dunbabin et al 2004), and specific software have been developed for analysis (Armengaud et al 2009;Ristova et al 2013;Galkovskyi et al 2012). It has long been known that root architecture and plasticity reveal a response of plants to scarce nutrients, and natural variation exists for these traits in different species, related to potassium (Kellermeier et al 2013;Jia et al 2008), nitrogen (De Pessemier et al 2013, and phosphorus availability (Wang et al 2010).…”